Dual in-situ mixing for extended tuning range of resonators

Abstract

A dual in-situ mixing approach for extended tuning range of resonators. In one embodiment, a dual in-situ mixing device tunes an input radio-frequency (RF) signal using a first mixer, a resonator body, and a second mixer. In one embodiment, the first mixer is coupled to receive the input RF signal and a local oscillator signal. The resonator body receives the output of the first mixer, and the second mixer is coupled to receive the output of the resonator body and the local oscillator signal to provide a tuned output RF signal as a function of the frequency of local oscillator signal.

1. An apparatus, comprising:
 a resonator body; 
 a driving electrode configured to drive resonation of the resonator body; 
 a sensing electrode configured to sense resonation of the resonator body; 
 a first non-linear mixer coupled to the resonator body, the first non-linear mixer configured to:
 receive a frequency of a first mixer input signal and a frequency of a local oscillator signal as input frequencies, 
 mix the received first mixer input signal with the local oscillator signal to produce a first mixed output signal from the first non-linear mixer, and 
 provide the first mixed output signal to the driving electrode of the resonator body; and 
 
 a second non-linear mixer coupled to the sensing electrode of the resonator body, the second non-linear mixer configured to:
 receive a frequency of the resonator body and the frequency of the local oscillator signal as input frequencies, 
 mix the received frequency of the resonator body with the local oscillator signal to produce a second mixed output signal from the second non-linear mixer, the second mixed output signal being an output signal having a tuned frequency as a function of the frequency of the local oscillator signal and having the same frequency as the first mixer input signal. 
 
 
     
     
       2. The apparatus of  claim 1 , wherein the resonator body, the first and second non-linear mixers are implemented as a Microelectromechanical systems (MEMS) resonator, wherein the MEMS resonator has an input and output non-linear transducers that operate as the first and second mixers, respectively. 
     
     
       3. The apparatus of  claim 2 , wherein the input and output non-linear transducers are drive and sense electrodes; and wherein the drive electrode and the sense electrode are non-linear lateral capacitive gaps. 
     
     
       4. The apparatus of  claim 3 , wherein the resonator body is a resonating square plate, and wherein the drive and sense electrodes are, respectively, each coupled to the resonating plate. 
     
     
       5. The apparatus of  claim 1 , wherein the resonator body is an optical resonator. 
     
     
       6. The apparatus of  claim 1 , further comprising a local oscillator to provide the local oscillator signal the resonator body. 
     
     
       7. The apparatus of  claim 6 , wherein the local oscillator is a Microelectromechanical systems (MEMS) oscillator. 
     
     
       8. The apparatus of  claim 7 , further comprising a switch coupled to the output of the MEMS oscillator, wherein the MEMS oscillator controls the switch to connect a bias source to the resonator body. 
     
     
       9. The apparatus of  claim 1 , wherein the first mixer input signal is a radio frequency (RF) input signal; and wherein the second mixed output signal is an RF output signal. 
     
     
       10. The apparatus of  claim 1 , wherein the resonator body is a beam, a plate, a cantilever arm or a tuning fork. 
     
     
       11. An apparatus, comprising:
 a resonating system having first and second non-linear elements and a resonating body coupled therebetween, the resonating body having a resonant frequency; and 
 an external frequency source coupled to provide an external frequency to each of the two non-linear elements of the resonating system; 
 where the first non-linear element is configured to receive an input signal having a first frequency and to provide an output signal having a second frequency that is different from the first frequency and that is based on a combination of the first frequency and the external frequency; 
 where the resonating body is configured to receive and filter the output signal from the first non-linear element to produce a filtered signal having the resonant frequency of the resonating body; and 
 where the second non-linear element is configured to receive the filtered signal from the resonating body and to combine the filtered signal with the external frequency to produce an output signal having the original first frequency of the input signal. 
 
     
     
       12. The apparatus of  claim 11 , further comprising means for extending a tuning range of the resonating system through the control of the external frequency source. 
     
     
       13. The apparatus of  claim 11 , wherein the resonating system comprises:
 a resonating square plate provided as the resonating body; 
 a drive electrode coupled to the resonating square plate, wherein the drive electrode is an input non-linear electrostatic transducer, wherein the drive electrode is one of the two non-linear elements; and 
 a sense electrode coupled to the resonating square plate, wherein the sense electrode is an output non-linear electrostatic transducer, wherein the sense electrode is the other of the two non-linear elements. 
 
     
     
       14. The apparatus of  claim 13 , wherein the drive electrode and the sense electrode are non-linear lateral capacitive gaps. 
     
     
       15. The apparatus of  claim 11 , wherein the resonating body is a beam, a plate, a cantilever arm or a tuning fork. 
     
     
       16. An apparatus, comprising:
 a resonator device having a non-linear input transducer and a non-linear output transducer; and 
 an external frequency source to provide a local oscillator signal to the resonator device, wherein the resonator device is configured to receive an input radio-frequency (RF) signal, and wherein the non-linear behavior of the input transducer operates as a first mixer to up-convert the input RF signal to a pass band frequency of the resonator device using the local oscillator signal, and wherein the non-linear behavior of the output transducer operates as a second mixer to down-covert a filtered signal output from the resonator device to the original RF frequency. 
 
     
     
       17. The apparatus of  claim 16 , wherein the resonator device comprises:
 a resonating square plate; 
 a drive electrode coupled to the resonating square plate, wherein the drive electrode is the non-linear input transducer; and 
 a sense electrode coupled to the resonating square plate, wherein the sense electrode is the non-linear output transducer; 
 where the external frequency source is coupled to provide the local oscillator signal to each of the drive electrode and the sense electrode. 
 
     
     
       18. The apparatus of  claim 17 , wherein the drive electrode and the sense electrode are non-linear lateral capacitive gaps. 
     
     
       19. The apparatus of  claim 16 , wherein the resonator device comprises a beam, a plate, a cantilever arm or a tuning fork. 
     
     
       20. A method, comprising:
 receiving an input radio-frequency (RF) signal having an input frequency; 
 filtering the input RF signal to provide an output RF signal, wherein filtering comprises:
 mixing the input frequency with a local oscillator frequency using a first non-linear element; 
 inputting the mixed frequency into a resonator body; and 
 mixing the output of the resonator body with the local oscillator frequency using a second non-linear element. 
 
 
     
     
       21. An apparatus, comprising:
 an antenna to receive a radio-frequency (RF) signal; and 
 a filter having a resonator device having a non-linear input transducer and a non-linear output transducer, wherein the filter is a programmable channel select filter by tuning a local oscillator frequency that is applied to each of the non-linear input transducer and the non-linear output transducer of the resonator device. 
 
     
     
       22. The apparatus of  claim 21 , further comprising:
 a wideband filter coupled to the antenna to filter the RF signal received by the antenna; and 
 a pre-amplifier coupled to the wideband filter and the filter having the resonator device, wherein the pre-amplifier amplify the filtered RF signal for impedance matching. 
 
     
     
       23. An apparatus, comprising:
 a plurality of filters, each corresponding to a channel and each comprising a resonator device having a non-linear input transducer and a non-linear output transducer; and 
 a plurality of local oscillators, wherein each of the plurality of local oscillators is configured to switch in and out of a receiver path the corresponding filter using a local oscillator signal. 
 
     
     
       24. The apparatus of  claim 23 , wherein two or more channels are turned on at the same time.